As more and more people choose to live in suburban area with bigger home sites, they get more threat of property damage from the migrating deer as well. It is commonly known that there is increasing damage and loss caused by the rising deer population, which, in search of food are migrating to populated suburban areas.
There is a need to deter animals, including domestic animals such as cats and dogs, together with many other animals from certain areas, but not hurt the animals in any way. Furthermore, there is a requirement to have a deterrent device for animals which does not harm the environment.
A very old way to deter animals from eating crops is to use humanoid dummies in the farm. Since these dummies do not move, do not act and do not make noise toward approaching animals to be repelled, the effectiveness is very limited. Newer ways to achieve deterring goal include spraying of specific chemicals in designated area, which is considered as a not environmental friendly way to do and the effect is deteriorating with increasing raining days. Using ultrasound, especially in specific generation pattern, is also a popular way to repel animals such as deer. U.S. Pat. Nos. 5,278,537, 5,418,518 and 5,602,523 are examples for such repelling system. The effectiveness, however, is generally not as good as desired.
A lot of attempts based on other schemes have also been proposed to repel animals to avoid damages. U.S. Pat. Nos. 5,009,192, 5,458,093 and 6,373,385 all provide devices which activate sprinklers when animals enter a certain area and provide several pulses of water until the animals move out of the area. Pulse type sprinklers have a definite tick noise as they move through an arc and these may be set up to be activated when an animal is detected in a specific area. They typically use solenoid valves to control the spray of water through sprinklers.
These devices, although proved to be effective, have a big drawback that a connecting pipe is needed to supply pressurized tap water for activating the sprinklers. Such piping line lying on the lawn, unless buried under ground, is not only a nuisance for the landscape, but also a trap for human and machine to move on the lawn surface and in general is considered as a headache for homeowner in the lawn mowing season.